Béarnaise is a tarragon-and-shallot reduction folded into the architecture of hollandaise — the same clarified-butter-into-warm-yolks emulsion, but built on a savoury, herbal, sharply acidic base that transforms it from brunch sauce to the definitive accompaniment to grilled beef, lamb, and fish. Where hollandaise whispers, béarnaise speaks. The reduction is where the dish lives or dies. Combine 60ml white wine vinegar, 60ml dry white wine, 2 finely minced shallots, 1 tablespoon cracked white peppercorns, and 3 tablespoons chopped fresh tarragon stems (reserve the leaves) in a small saucepan. Reduce over medium heat at 85–90°C (185–194°F) until only 2 tablespoons of syrupy, intensely aromatic liquid remain — roughly 8–10 minutes. This reduction concentrates the acetic acid, the volatile aromatics of tarragon (estragole), and the allium sweetness of the shallots into a potent flavour base that no amount of last-minute seasoning could replicate. Strain through a fine-mesh sieve, pressing the solids firmly with a spoon to extract every drop of flavour. Discard the solids. Cool the reduction to 40°C (104°F). From here, the technique mirrors hollandaise precisely: whisk 3 egg yolks with the strained reduction over a bain-marie at 55–60°C (131–140°F) until the ribbon stage, then incorporate 200–250g clarified butter in a thin stream, whisking constantly. The temperature ceiling remains 65°C (149°F) at the yolk. Season with fine salt and a squeeze of lemon if needed. Finish by folding in 1 tablespoon of finely chopped fresh tarragon leaves and 1 teaspoon of fresh chervil. These go in off the heat, at the very end, because heat destroys their delicate volatile oils within seconds. The finished sauce should be pale gold flecked with green herbs, thick enough to coat a spoon but loose enough to pour in a slow ribbon. It should smell of tarragon first — anise-sweet, green, slightly peppery — then butter, then a sharp vinegar backbone. On the tongue, the acid should hit first, then the rich butter, then the tarragon’s lingering warmth. If all three registers are present and distinct, the sauce is correct.
Quality hierarchy: 1) Tarragon quality — French tarragon (Artemisia dracunculus var. sativa) only. Russian tarragon (var. inodora) has almost no flavour and is the reason most home-cooked béarnaise tastes like bland hollandaise with green bits in it. French tarragon has a strong anise scent when you crush a leaf between your fingers; Russian tarragon smells like grass. This single ingredient choice separates a great béarnaise from a forgettable one. 2) Reduction intensity — the liquid must reduce by at least 75%. Under-reduced béarnaise has a thin, watery acidity instead of a concentrated, syrupy punch. The consistency of the cooled reduction should be almost viscous. 3) Shallot fineness — mince the shallots as finely as possible so they release maximum flavour into the reduction. Large pieces retain their goodness inside the cell walls and get strained out before contributing. 4) Double tarragon — stems in the reduction for backbone flavour (they’re more robust and survive heat), leaves folded in at the end for fresh, bright aroma. This two-stage approach gives the sauce depth and lift simultaneously. 5) White pepper, not black — black peppercorns leave visible dark specks in the strained sauce and have a harsher, more pungent bite. White peppercorns provide clean heat that integrates seamlessly.
Make the reduction in advance. It keeps refrigerated for a week and is the time-consuming part of the sauce. At service, bring it to room temperature and proceed with the yolks and butter — the sauce comes together in 8 minutes. For a choron sauce (béarnaise’s tomato cousin): fold 2 tablespoons of reduced, concentrated tomato fondue into the finished béarnaise. The tomato adds sweetness and colour that pairs magnificently with grilled lamb. For a paloise sauce: replace the tarragon with fresh mint — same reduction technique, same emulsion, but a bright, cooling finish that cuts through rich lamb fat. Béarnaise and steak: the sauce goes beside the steak, not on top. Pooled on the plate at two o’clock, so the diner controls every bite. A steak smothered in béarnaise is a missed opportunity for contrast. Temperature for service: 50–55°C (122–131°F). Warm enough to be fluid, cool enough that the emulsion holds.
Using Russian tarragon — the most common and most damaging error. If the tarragon doesn’t smell strongly of anise, do not proceed. Using dried tarragon in the final garnish — dried tarragon has a different, more bitter flavour profile. It works in the reduction (where it’s tempered by heat and acid) but not as the raw finish. The reduction should always use fresh. Not reducing enough — if the reduction is thin and sharp rather than syrupy and concentrated, the final sauce will taste acidic and one-dimensional. Reduce further than you think you need to. Adding the fresh herb garnish while the sauce is still over heat — 30 seconds of bain-marie heat turns fresh tarragon from bright and anise-sweet to dull and bitter. Off heat, always. Breaking the emulsion by rushing the butter — béarnaise breaks for all the same reasons hollandaise does. The fix is the same: ice water and aggressive whisking, or start with a new yolk.